Author(s): Chen, RF (Chen, Renfeng); Chen, KX (Chen, Kaixuan); Ran, JX (Ran, Junxue); Song, YJ (Song, Yijian); Qu, XD (Qu, Xiaodong); Yang, KW (Yang, Kewei); Ji, XL (Ji, Xiaoli); Wang, JX (Wang, Junxi); Wei, TB (Wei, Tongbo)

Source: SEMICONDUCTOR SCIENCE AND TECHNOLOGY Volume: 39  Issue: 7  Article Number: 075022  

DOI: 10.1088/1361-6641/ad54e8  Published Date: 2024 JUL 1  

Abstract: We have demonstrated an effective piezoelectric polarized interface modulation in a GaN/Ti Schottky structure and fabricated a flexible GaN-based sensor using a double-transfer method. Chemical etching of the Ni sacrificial layer successfully removes the temporary substrate without damaging the metal electrodes. The fabricated flexible GaN-based sensor, with top and bottom Ti metal Schottky contacts, exhibits a current on/off characteristic under external strain. Specifically, the current shows a 53.9% reduction under 2.3% tensile strain and a 67.8% enhancement under -2.3% compressive strain at a 5 V bias voltage. It was found that the light/dark current ratio in the GaN/Ti Schottky junction significantly increases near zero-bias voltage under 2.3% tensile strain, likely indicating an enhanced built-in piezoelectric polarized field at the interface. This work advances the study of flexible sensors based on wurtzite III-V nitrides for wearable electronics and optoelectronics.